铁路车辆用Q450EWR1耐候钢耐蚀性能研究

STUDY ON CORROSION RESISTANCE OF Q450EWR1 WEATHERING STEEL FOR RAILWAY VEHICLES

采用周期浸润腐蚀试验方法,对热轧高耐候钢Q450EWR1进行了腐蚀性能检测。根据失重率计算公式,分析了Q450EWR1钢的腐蚀速率变化规律,并采用SEM、XRD、电子探针对腐蚀锈层进行了组织观察、物相分析及元素分布分析。结果表明,随着腐蚀时间的增加,Q450EWR1钢的失重率逐渐下降,腐蚀时间大于168 h时,失重率趋于稳定;腐蚀产物由疏松多孔状向致密的块状变化;物相组成由γ-FeOOH向α-FeOOH转变,结构更加致密;腐蚀周期内,锈层截面孔洞处出现明显的Cr元素富集。与Q345B钢相比,Q450EWR1钢的力学性能及耐腐蚀性能更好。

The corrosion performance of hot rolled high weather steel Q450EWR1 was tested by periodic immersion corrosion test.According to the calculation formula of weight loss rate,the corrosion rate of Q450EWR1 steel was analyzed.And SEM,XRD and EPMA were used to observe the structure,phase and element distribution of the corrosion layer.The results show that with the increasing of corrosion time,the weight loss rate of Q450EWR1 steel decreases gradually,and when the corrosion time is more than 168 h,the weight loss rate tends to be stable;the corrosion products change from loose porous to dense block;the phase composition changes fromγ-FeOOH toα-FeOOH with more compact structure;there is obvious Cr enrichment in the pores of rust layer section during the corrosion period.Compared with Q345B steel,Q450EWR1 steel has better mechanical properties and corrosion resistance.